

What does kWh mean? It means "kiloWatt hours" or 1,000 Watts per hour  a measure of how many kiloWatts were generated/used within 1 hour of time. For example, if you have a really inefficient halogen lamp with a 300Watt bulb and you leave it turned on, it will use 300 Watts (0.3 kW) per hour and consume 7.2 kWh within just 1 day (24 hours × 0.3 kW = 7.2 kWh). Lets say you use that lamp for 3 hours per day every day for a year, it will consume 328.5 kWh. So, if your energy costs 10¢ per kWh, that lamp alone will cost you $32.85/year to operate. That may not seem like much, but that's just one lamp. Add up all of the lamps and appliances in your house, and you begin to see where all of your money is going. 
Month  The given month for which data is displayed here. The months are shown with an overall average first and then most recent on top. 
kWh Estimate  How many kWh our solar system is expected to produce in the given month, based on calculations provided by the installer, Standard Solar. 
Our Production  How many kWh our solar system actually produced in the given month. Solar production, as you might expect, is governed primarily by the weather, but it also involves other factors. These include the angle of the sun and the hours of sunlight per day (both being lower in winter and higher in summer). Power outages also reduce production (because it is tied to the grid, when the grid fails, so does our solar system). 
% Efficient  How efficient our solar system was compared to the original kWh Estimate. Calculated as Our Production divided by kWh Estimate. 
Average Use  A 3year average of kWh used by our entire house in the given month. 
% Offset By Solar  A percentage estimating how many kWh used by our house was generated by solar. Calculated as Our Production divided by Average Use. 
Monthly Savings  How much money in power company charges was saved by not having to buy it. This includes all perkWh generation & distribution costs. It's based on our Average Use minus the kWh bought multiplied by their perkWh charges. 
MWh Sold 
MegaWatt hours sold  When excess energy is produced that our home doesn't use, it is automatically used by the grid. When that surplus energy hits one MegaWatt hour (1 MWh) it is sold on the open energy generation market as an SREC (Solar Renewable Energy Credit). We go through a broker who sells them for us, and they sell them on a quarterly basis. That's why you'll see nothing for 3 months, and then a large amount. When we started, we earned a fixed rate of $220 per SREC through a 3year contract with our broker. The rate has dropped to $150. 
Lifetime Savings  A sum of all Monthly Savings and MWh Sold so far. 
Notes  Notes to describe what the month was like. 